I have the shakes bad!

If this isn't death wobble then I don't know what is...

For a few months I've had a vibration. It started out very minor, then I went to Big Bear and it got worse. At that point above 65mph my front end would start to shake, we found that it appeared to be the axle moving in a left/right manner. Anyway, upon inspection I found the track bar to be bad. I replaced it, the problem still existed, this time I found the drag link to pitman arm joint to be bad. Today I replaced that joint and the steering stablizer (and checked the torque of all components).

Anyway, at first everything seemed fine. I hit 80mph then backed off a bit. After driving at about 70 - 75mph for four or five minutes it struck...with a vengence, I'm talking turned up to 11! It shook so bad it made the crack in my windshield longer! I had to brake (duh!), it kept getting more and more violent, while breaking I could swear I felt the whole left hand side of the car (front and rear jump. It didn't go away until 40mph (and yes, I got promptly off the freeway and poked around with a flashlight.

Any ideas?

Here's what I have: '89 XJ, 3" lift, stock UCA's and LCA's, no sway bar (my mount is broken), stock steering setup, Rancho 5000 shocks. I put the lift on about two and a half years ago and have never had a problem with shakes and rattles.

Here's what I've done: Replaced track bar (I checked it with somebody behind the wheel turning and me feeling, it's tight), Replaced drag link to pitman arm joint, replaced steering stabilizer (all of these parts had slop in them when doing the wheel turn trick, nothing else did.)

Here's what I'm doing: On Thursday I will be getting a new drag link and tie rod (I was planning on not doing the joint until then but the problem had gotten worse). I am also replacing the UCA's and LCA's with stock new units (they were cheap, and I'm sure my bushings are bad). I will probably align my tires tomorrow if I can get the time, I will also get a professional alignment done after I complete the work up there.

Sequoia

PS: I'm glad I didn't have a full bladder when that happened, I would have fouled my seat!

Oh, one more thing, I forgot to mention that I also checked the torque of the steering box and all front end components.

You have DW, Have you checked the ball joints? Also whens the last time the tires were balanced?

Don't waste your money on a professional alignment. I have yet to have a successful alignment from a shop. I always end up re-doing it myself when I get home.

Dan

i say get it professionally aligned. after all the new parts your putting on, it would make sense to go some where that will align the wheels, balance the tires, and give you the alignment readout. this info and service is invalueable when trying to figure out death wobble.

i use to get dw all the time. i went and got a professional alignment just so i could get the readout sheet. then i adjusted it from there. the only difference is my whole front end is adjustable and i built a crossover setup for my steering. let them set your toe in and remeber that for future reference. if you had adj upper and lower arms it is cake to set the caster angle and wheelbase lenght. you might need to get the shims to move your stock lower ca farther out. my main culprit was the track bar. with the lift it pulled the axle to one side so a adj one took its place with a drop bracket and all is well. after recentering the axle and tracking it with the rear tires even my bump steer went away. for only a 3 inch lift you could probably drill a new hole for the track bar. hth

You have death wobble. However, IMHO I feel there's a crying need to differentiate between things that "cause" death wobble, and things that allow it to happen/get worse.

For the record, as I've said before the one and only time I ever experienced true death wobble was in a box-stock 1999 WJ Grand Cherokee with less than 14,000 miles on the odometer, never been off road. Nothing in the front end was worn or damaged. Conversely, I drove my '88 XJ for almost a year with a trashed axle-emd bushing on the track bar. I had a tremendous amoutn of wander, but even with slightly out of balance tires I didn't have DW.

Death wobble is caused by tire balance. Wheel shimmy or tramp escalates into death wobble when conditions allow the shaking on one wheel to be transferred back through the steering and suspension to the opposite wheel. In the case of the 1999 WJ, what set it off was a pair of badly warped rotors.

CHW of the NAC had death wobble and after a lot of diagnosis found that the ball joints were bad. However, tight ball joints don't correct for wheel balance, they simply help stop an unbalanced wheel from shaking so violently that the motion gets transferred to the opposite wheel.

Get an alignment, and get the wheel balanced.

In addition....

As Eagle said Death Wobble does not have to be exerienced in a vehicle with a worn component in the suspension. A friend with a '95 1 ton Dodge Dually had the same violent front end shake experience when the vehicle was nearly new. As is the case so often the stock tires wore quickly on this truck. He replaced them with another make. Shortly after while driving down the road he ran across a bridge approach crack that set off the DW. Said it almost made him wreck before he could slow things down. The thing that caused this was simply the new tires. Not a thing was wrong with the tires per se, but they had added the 'resonance' quality to the front suspension that allowed this to happen. I advised a change to stiffer shocks to change the total resonsonance dynamic in the front end. All has been totally okay with the truck and the tires are still on it. I think a coil sprung solid front axle may tend to have more of a problem with this due to the compliance the coils add.

However, a worn/bent part is usually the culprit. The factory ordinarily designs a suspension fairly resistant to harmnic feedbacks that build to a DW level. From what i have been reading, perhaps these Jeeps are more susceptible to DW than most, but is usually from a worn component or two.